The instant invention relates to apparatus for accumulating sheets of paper being fed in a horizontal plane seriatim into a stack and more particularly to such apparatus wherein almost no gap is required between the sheets as they are being fed seriatim.
In the process of inserting sheets of paper into envelopes, typically the sheets of paper are fed seriatim in a horizontal plane from upstream paper handling apparatus, such as document feeders or bursters, toward an accumulating device and then downstream to other paper handling apparatus, such as folders or inserters. The accumulator functions to collect a plurality of documents against a registration edge and form a registered collation which can be further processed.
A typical accumulator has a pair of feed rollers which receive sheets seriatim from an upstream, horizontal conveyor and feed the sheets onto an accumulating deck. The first sheet to be deposited on the accumulator deck becomes the bottom sheet, and each succeeding sheet deposited lies on top of the preceding sheet. It is obviously desirable to accumulate the sheets at the maximum possible speed consistent with the capability of the upstream and downstream apparatus. Conventional accumulators require that there be a significant gap, on the order of 2 to 6 inches, between the sheets on the conveyor prior to their being deposited on the accumulator deck to assure proper accumulating. The instant invention eliminates the need for a large gap between sheets on a horizontal conveyor and permits the conveyor upstream of the accumulator to feed sheets having gaps as small as 1/8 inch or less. Consequently, the throughput of the accumulator and all of the associated apparatus is increased without any increase in the speed of the conveyor or other apparatus associated with the accumulator.